Linux no longer has support for the 80386 CPU. this is the first CPU to run Linux and now that it is so outdated; it is time that support was dropped for this ancient CPU. Linux has so many features nowadays that it makes no sense to support an ancient 386 CPU when there are cheap minicomputers like the Arduino and the Rasberry PI that allow the running of Xorg and minimal window managers with HDMI output and networking for a cheap price. It is unlikely that anyone these days would still be running an ancient 386 CPU anyway. There is a posting on Slashdot that tells the story of a person that installed Linux onto a 386 laptop; since the support for the 386 CPU was dwindling even back then; he had to use an ancient version of the Debian distribution to be able to install it. Read it here: http://linux.slashdot.org/story/11/08/13/1341240/installing-linux-on-a-386-laptop. This is quite an interesting hack, but I wonder how well the Linux distribution ran on such a slow computer. The 386 belongs to a distant age when you needed to install a separate math coprocessor to improve the speed of your computer. But that was a while ago.
A Pentium 4 computer could be bought for a very cheap price these days and would provide better performance than an old 386 ever would. You can only use 16 megabytes of RAM on a 386 and that would bog down if you had a few applications open. But old computes could still do some amazing things; there were Battletech centres in the old days that used computers with 32 megabytes of RAM to render 3D graphics and full motion video to create an immersive environment for multiplayer arcade gaming. Youtube link: Beyond 2000. These computers were quite advanced for their day. Nowadays multiplayer on-line gaming is very common; but using servers and client computers with performance far beyond the expectations of the reporters of the early 1990`s. Even a modern GPU by itself has far more power than an entire computer in the 90`s. I wonder if a Battletech centre would take off with modern technology. I guess that everyone can play these games on their own powerful gaming machines. I am sure that you could install something like NetBSD or FreeBSD onto a 80486, but the main problem would be disk space. If you had a 500 megabyte hard disk then you would have problems unless you only installed a base system and not many packages. But a Pentium 4 would make a better system to install Linux or UNIX to, you could use a multi-gigabyte hard disk and install /usr/ports and a Gnome desktop.
The first system I installed Red Hat 6.2 onto was a Celeron 600 with how much RAM I can not remember and it worked perfectly. I liked the fact I did not need to install countless drivers to get the hardware working. But the main Linux machine I used for years was a Pentium II 350 MMX with 192 Megabytes of RAM. That computer was my mainstay for a long while. I remember installing Debian 3.0 onto it a couple of times and having to compile a new 2.4 kernel to replace the existing 2.2 kernel to get my hardware working. But that was good fun and the KDE 2.2 desktop was very usable and fast enough for day to day use. But installing Linux onto a 386 would be very painful as the hardware is so slow; you are better off with a 486 SX or a Pentium II. A Pentium II can run KDE 3.4 and Gnome 2. That is better than an ancient 386 even with a math coprocessor. It would take all day to compile a kernel for gods sake. But if you like suffering then by all means go for it. Dropping support for the 386 CPU makes sense if no one is really using that CPU anymore, the kernel team can focus on more important things and not worry about supporting such outdated hardware. I wonder if the support for XT hard disks is still in the kernel? How would you attach these to a modern computer anyway? There is some information about this kernel module here. But it is pretty unlikely that you would have one of these laying around. Like those massive 8 inch floppy disk drives; they were seriously heavy. I used to have a couple of those.
But good luck trying to hook up those to a modern computer. These debuted in 1971 with a massive 100 kilobytes of storage space. That was a lot back then; that is 100,000 characters of text. The Radio Shack TRS-80 in 1979 included a built-in 8 inch floppy disk drive that could store 500,000 kilobytes of data. This computer had up to 64 kilobytes of RAM to work with and could use a line printer to print documents. The TRS-80 was pretty good for its time. The Tandy 1000 computer was also good to use for writing and running simple games coded in BASIC. The TRS-80 was a computer with the screen and computer all in one. The more modern Imac did the same thing; only the keyboard and mouse was separate. And the modern Macintosh computers with a huge screen and the disk drive and USB ports in the side of the machine. We used to think that a 1.44 megabyte floppy disk was a lot of portable storage; now we can use 2 terabyte portable hard disks that in practice store 1.8 terabytes and can hold a heap of movies. Better than the old days of carrying around VHS tapes to go to a friends house and have a movie session. You could not have imagined in the early days that we would be streaming movies off the Internet on Youtube. That is how far things have come since 1971.